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Titolo:
H-1-NMR STUDIES ON THYMOPOIETIN-TYPE OLIGOPEPTIDES - ASSIGNMENT OF THE PROTON RESONANCES AND INVESTIGATION OF CONFORMATIONAL PREFERENCES
Autore:
GUO W; NOSZAL B; SCHON I; NYEKI O;
Indirizzi:
LORAND EOTVOS UNIV,DEPT INORGAN & ANALYT CHEM,POB 32 H-1518 BUDAPEST 112 HUNGARY LORAND EOTVOS UNIV,DEPT INORGAN & ANALYT CHEM,POB 32 H-1518 BUDAPEST 112 HUNGARY UNIV CALIF RIVERSIDE,DEPT CHEM RIVERSIDE CA 92521 GEDEON RICHTER,CHEM WORKS H-1475 BUDAPEST 10 HUNGARY
Titolo Testata:
Journal of pharmaceutical and biomedical analysis
fascicolo: 7, volume: 11, anno: 1993,
pagine: 541 - 547
SICI:
0731-7085(1993)11:7<541:HSOTO->2.0.ZU;2-D
Fonte:
ISI
Lingua:
ENG
Soggetto:
NUCLEAR MAGNETIC-RESONANCE; DISULFIDE INTERCHANGE REACTIONS; THYMIC HORMONE THYMOPOIETIN; TRANSVERSE RELAXATION; THYMOPENTIN ANALOGS; BIOLOGICAL-ACTIVITY; AQUEOUS-SOLUTIONS; WATER RESONANCE; ROTATING-FRAME; SPECTROSCOPY;
Keywords:
THYMOPOIETIN; H-1-NMR SPECTROSCOPY; CHEMICAL SHIFT ASSIGNMENTS; TOCSY; ROESY; COUPLING CONSTANTS; CONFORMATION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
24
Recensione:
Indirizzi per estratti:
Citazione:
W. Guo et al., "H-1-NMR STUDIES ON THYMOPOIETIN-TYPE OLIGOPEPTIDES - ASSIGNMENT OF THE PROTON RESONANCES AND INVESTIGATION OF CONFORMATIONAL PREFERENCES", Journal of pharmaceutical and biomedical analysis, 11(7), 1993, pp. 541-547

Abstract

The thymopoietin-type tripeptides TP3 (HArg-Lys-AspOH), TP(D-Asp)3(HArg-Lys-D-AspOH) and tetrapeptide TP4 (HArg-Lys-Asp-ValOH) were studiedby one- and two-dimensional, 500 MHz H-1-NMR spectroscopy in H2O and D2O solutions at four different pH values. All proton resonances of the three oligopeptides were assigned by two-dimensional phase-sensitiveTOCSY experiments at pH 12.2. 9.1. 5.9 and 3.6. At these pH-values well-defined stages of protonation and concomitant molecular charges exist, allowing different possibilities for intra-molecular and inter-residual orientations. Conformation-sensitive rotating frame nuclear Overhauser enhancement (ROESY) two-dimensional experiments were also performed at the above pH values. These experiments indicated no definite solution conformation of any of the molecules at any pH. Standard one-dimensional experiments were also carried out and three-bond coupling constants were measured for the NH-CH and the Asp CH-CH moieties. The coupling constants provided evidence that non-statistical orientations of the functional groups exist which are changed upon protonation of the basic sites.

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Documento generato il 15/07/20 alle ore 08:28:39